An optoelectronic device such as a photovoltaic cell, a light emitting diode (LED), or an organic light emitting diode (organic LED) may include an encapsulant encapsulating an optical emission region or optical sensing region of a device.
For example, a solar cell module may be generally manufactured by a lamination method including laminating a transparent front substrate that is a light-receiving substrate, an encapsulant, a photovoltaic element, an encapsulant, and a back sheet, and then hot-pressing the laminate thus laminated while vacuum-aspirating the laminate.
As an encapsulant used for a solar cell module, an ethylene-vinyl acetate (EVA) resin is most often used in view of processability, buildability, costs, and the like.
However, the EVA resin has low adhesive strength with respect to an element, such as a front substrate or a back sheet, which is in contact with an encapsulant included in an optoelectronic device. Therefore, when the module is exposed outdoors for a long period of time, there is a problem in that interlayer peeling is easily likely to occur. In addition, during manufacturing a solar cell module using an encapsulant including an EVA resin, the EVA resin may be subject to a pyrolysis according to a hot-pressing condition, and thereby, acetic acid gas may be generated. The acetic acid gas aggravates a working environment, has a bad influence on a photovoltaic element or electrode included in a solar cell module, and also causes deterioration of the module, decline of generating efficiency, and the like.
Therefore, a demand for an encapsulant for an optoelectronic device having an improved long-term adhesive property has lasted.